Prokaryotes & evolution of metabolism Flashcards
What are the earliest organisms called
Prokaryotes (Pro= before, karyos=nucleus)
Describe prokaryotes (5)
- Most ancient organism
- Unicellular
- Lived alone for 2 bill yrs
- Greatest diversity of lifestyles and habitats
- Created the Earth we know
3 prokaryote domains?
Archaea, Bacteria, Eukarya (protists, fungi, plants, animals)
Difference between prokaryotic and eukaryotic cells? (5)
Prokaryotic cells are smaller, single membraned systems not double, nucleoid, no walled organisms, no cytoskeleton
Describe bacteria (3)
- Includes most prokaryotes
- Hugely diverse in metabolism and structure
- Include photosynthetic cyanobacteria, some disease organisms
I.e. samonella
Describe archaea (1) and two differences from bacteria
- Live in harsh and extreme envrionments (extremophiles)
- Difference between bacteria is cell wall composition and details of protein synthesis
i.e. halophiles and strain 121
Why are modern prokaryotes clues to evolution of metabolism
- Some modern prokaryotes live in envrionments similar to those in early Earth; metabolism of these groups similar to those of ancient group
What are photo-autotrphs
Use light as energy, and Co2 ch4 etc. as carbon sources
What are photo-heterotroph
Use light as energy, and organics as carbon sources
What are chemo-organo-autotroph
Use organics as energy, and co2 ch4 etc. as carbon sources
What are chemo-organo- heterotraph
Use organics as energy, and organics as caron sources
What are chemo-litho-autotroph
Use inorganics as energy, and co2 ch4 etc. as carbon sources
What are chemo-litho-heterotrophs
Use inorganics as energy, and organics as carbon sources
What respiratory mode do obligate anaeroby use
Fermentaton/anaerobic respiration
What respiratory mode do faculative anaeroby use
O2 if present, or fermentation
